DataMine2 - correpted raw data after restart

Hi,

Since some time I am struggling a lot with raw data files from my energy meter which are stored in datamine USB drive. 

The strange thing is when Vera restarts (I am not sure if manual or automatic (power failures) is causing the problem), my raw data from energy meter gets heavly corrupted like below.
The weired this is that it is happening ONLY for power meter. It just started to appear after recent upgrade of Vera. I did not change anything in the configuration. It is very annoying because it is taking a lot of time to changeit manually. Any suggestions??

14208"754w,2605.56<0
152082760?,2605.5664
!:0827668,r605.5682
1%20825728,2645.5700
152 825308,260/=720
152082784<,2605.5740
15208079x8,2605.57&
15:0827968,2605.5780
1?20828028,2605.5:00
1%20828088,3605.5820
1520828148,2’45.4x50
1520828208,2?05.5880
152886<268,2605.5910
520828328,2605.59<0
1520828388,2605.597005209"848,6605.60p0
1520809508,2605.6030
152082856?,2605.6450
15r082(628,2605.6450
1520?28688,2605.6060
15208283?8,2?p5.6070
1508288?,2605.6080
1520828868,2605.6100
1520828928,2605.6q30
1520808988,2605.6160*152829048,r605.6190
1520829108,2605.>"20
15208291?8,2605.6250
1520829230,2605.7280
15208:9696,2605.23101520809348,3405.6341
1520829408,2605.6370
1?20829468,r405.>400?1=20829528,2605.64;0
1520829588-26?5.7460

Looks like a corrupted USB stick? Have you been using it a while?

Not more than 6-8 months. Normally it works pretty OK. Such issues are happening only when Vera reboots, not during normal operational mode. It is like the the USB drive is not unmounted properly when restart is happening and the file system becomes faulty.
And additionally not all the .txt files are wrong.
What is more funny, the problem is related to historical txt files, which are old (for example from February).